A micromechanical inspired model for the coupled to damage elasto-plastic behavior of geomaterials under compression

We propose an elasto-plastic model coupled with damage for the behavior of geomaterials in compression. The model is based on the properties, shown in [S. Andrieux, et al., Un modele de materiau microfissure pour les betons et les roches, J. Mecanique Theorique Appliquee 5 (1986) 471-513], of microcracked materials when the microcracks are closed with a friction between their lips. That leads to a macroscopic model coupling damage and plasticity where the plasticity yield criterion is of the Drucker-Prager type with kinematical hardening. Adopting an associative flow rule for the plasticity and a standard energetic criterion for damage, the properties of such a model are illustrated in a triaxial test with a fixed confining pressure.